used to be all you needed was a pulse if you came from an anesthesia residency. now it's a different story. i'm graduating this yr and doing pain it was alot more competitive than I anticipated.
every program looked at in-training scores, USMLE scores and med school transcripts. the problem is that not every anesthesia program has a pain fellowship attached(so limited number of pain fellowships) AND the fellowships only have 2 or 3 positions
you definitely have a leg up graduating from anesthesia instead of PM&R, neurology and even psych(yes, emory had a few psych residents apply!) but there are several anesthesia residents that are opting for the pain track